Online forms will often get abused by bots and scripts and other visitors that you don't want to hear from, causing you to receive lots of submissions you don't want or need.
Luckily there are ways to reduce this issue significantly.
Among other providers, Google has a free script called reCAPTCHA that you can easily add to all your forms. This script will prevent abuse from bots/scripts while still allowing your legitimate visitors to submit your form without any hassle. They even have a version that is invisible to the user so that they don't even have to type or click anything.
Here is a link to learn more about reCAPTCHA from Google:
If you would like to use ReCAPTCHA to protect your download links, see this article:
We hope this helps but if you need any further assistance don't hesitate to reach out to our support team!